In an up to date checkout of py3k on Gentoo linux with LC_CTYPE=en_US.UTF-8, I get a failure in test_sys:
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FAIL: test_pythonfsencoding (test.test_sys.SysModuleTest)
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Traceback (most recent call last):
File "/home/rdmurray/python/py3k/Lib/test/test_sys.py", line 605, in test_pythonfsencoding
self.check_fsencoding(get_fsencoding(env), 'ascii')
File "/home/rdmurray/python/py3k/Lib/test/test_sys.py", line 573, in check_fsencoding
self.assertEqual(fs_encoding, expected)
AssertionError: 'utf-8' != 'ascii'
- utf-8
+ ascii